我是一名学生，对于Android开发更新鲜。
经过大量研究，我已成功为我的项目实施了RecycleView。在我的项目中，当用户长时间点击RecyclerView中的行时，他会获得一个复选框和一个删除按钮，用于删除该行的所有行。但我想要的是当用户长时间点击任何一行时。只有该行的特定复选框或删除按钮才会显示。并且要选择其他行，他可以单击它们，它们将被选中，然后具有全局删除按钮，可以删除用户选择的任何行。我可以看到的任何建议或博客？ 的 MyCustomAdapter
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.CustomRecyclerViewHolder>{
List<RecyclerViewClass> mItems;
Context mContext;
boolean onLongPressReceived = false;
UpdateMainClass updateMainClass;
/**
* Contructor to initialize context and list items.
* @param context Context of the Activity on which RecyclerView is initialised
* @param items List of POJO object that contains the data to update the rows
*/
public CustomAdapter(Context context, List<RecyclerViewClass> items){
mContext = context;
mItems = items;
//Check whether the Activity implements UpdateMainClass Interface or not
if(context instanceof UpdateMainClass){
updateMainClass = (UpdateMainClass)context;
}
}
/**
* <p>This method updates the long press status variable when called from the Activity</p>
* <p>Helpful to prevent any unwanted changes to status variable</p>
* @param status tell whether whether long press is clicked or not
*/
public void setOnLongPressStatus(boolean status){
onLongPressReceived = status;
notifyDataSetChanged();
}
/**
* Provides the long press status to the Activity
* @return longPressReceived status
*/
public boolean getLongPressStatus(){
return onLongPressReceived;
}
@Override
public CustomRecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View v = LayoutInflater.from(mContext).inflate(R.layout.custom_recyclerview_layout, parent, false);
//set the margin if any, will be discussed in next blog
return new CustomRecyclerViewHolder(v);
}
@Override
public void onBindViewHolder(final CustomRecyclerViewHolder holder, int position) {
holder.mAvatarView.setImageDrawable(mItems.get(position).getmImage_url());
holder.mMsg1.setText(mItems.get(position).getMessage1());
holder.mMsg2.setText(mItems.get(position).getMessage2());
/**
* <p>Enable the row delete and select layout and
* Colors the background based on check box status if onLongPressReceived variable is set to true</p>
* <p>Otherwise renders a regular white background list with visible checkboxes that are selected.</p>
*/
if(onLongPressReceived) {
holder.checkboxHolder.setVisibility(View.VISIBLE);
holder.mCheckBox.setChecked(mItems.get(position).getmIsChecked());
holder.mDeleteRow.setVisibility(View.VISIBLE);
if(mItems.get(holder.getAdapterPosition()).getmIsChecked()){
holder.cardView.setBackgroundColor(ContextCompat.getColor(mContext, R.color.list_selected));
}else {
//holder.cardView.setBackgroundColor(ContextCompat.getColor(mContext, R.color.list_long_pressed));
}
}
//Checking whether a particular view is clicked or not
else{
holder.cardView.setBackgroundColor(ContextCompat.getColor(mContext, R.color.list_unselected));
holder.mDeleteRow.setVisibility(View.INVISIBLE);
if (mItems.get(position).getmIsChecked()) {
holder.checkboxHolder.setVisibility(View.VISIBLE);
holder.mCheckBox.setChecked(true);
} else {
holder.checkboxHolder.setVisibility(View.GONE);
holder.mCheckBox.setChecked(false);
}
}
//Calls the interface method in Activity to respond to CheckBox changes
holder.mCheckBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
System.out.println("Holder Position is: " + holder.getAdapterPosition());
System.out.println("Holder Boolean is " + b);
updateMainClass.updateListBackground(holder.getAdapterPosition(), b);
}
});
/**
* <p>Responds to long press made on any row</p>
* <p>Checks the item on which long press is made
* sets the onLongPressReceived status to true and notify the adapter to refresh the list.</p>
*/
holder.cardView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
onLongPressReceived = true;
mItems.get(holder.getAdapterPosition()).setmIsChecked(true);
notifyDataSetChanged();
return true;
}
});
//Calls the interface in Activity to remove the item from the List.
holder.mDeleteRow.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
updateMainClass.updateItemList(holder.getAdapterPosition());
}
});
}
@Override
public int getItemCount() {
return mItems.size();
}
public class CustomRecyclerViewHolder extends RecyclerView.ViewHolder{
private TextView mMsg1, mMsg2;
private ImageView mAvatarView;
private CheckBox mCheckBox;
private LinearLayout checkboxHolder;
private ImageView mDeleteRow;
private CardView cardView;
/**
* Initializes all the views of a ViewHolder
* @param itemView parent view in which all the List Item views are present
*/
public CustomRecyclerViewHolder(View itemView) {
super(itemView);
mMsg1 = (TextView)itemView.findViewById(R.id.text_view1);
mMsg2 = (TextView)itemView.findViewById(R.id.text_view2);
mAvatarView = (ImageView)itemView.findViewById(R.id.avatar_holder);
mCheckBox = (CheckBox)itemView.findViewById(R.id.checkbox);
checkboxHolder = (LinearLayout)itemView.findViewById(R.id.checkbox_holder);
mDeleteRow = (ImageView)itemView.findViewById(R.id.delete_row);
cardView = (CardView)itemView.findViewById(R.id.card_holder);
}
}
public interface UpdateMainClass{
void updateItemList(int position);
void updateListBackground(int position, boolean isChecked);
}
}
答案 0 :(得分：0)
从this类对您的适配器进行子类化。然后在长时间单击一个视图后选择该视图并在单击后切换所选视图，如下所示。 boolean longClicked = false;
@Override
public void OnItemClickListener(View v,int position){
if(longClicked){
mAdapter.toggleSelection(position);
return;
}
//normal click functionality here
}
@Override
public boolean OnItemLongClick(View v,int position){
longClicked = true;
mAdapter.toggleSelection(position);
}
选择要删除的所有项目后，您可以从适配器获取所选位置mAdapter.getSelectedItems()
注意：
完成对selectedItems的操作完成后，不要忘记将longClicked重置为false。